function Circle () {
  this.startRadio = 0
  this.endRadio = Math.PI
  this.color = '#f9763f'
}

Circle.prototype.draw = function (ctx, centerX, centerY) {
  ctx.strokeStyle = this.color
  ctx.lineWidth = 10
  ctx.beginPath()
  ctx.globalCompositeOperation = 'destination-over'
  ctx.lineCap = 'round'
  // ctx.arc(centerX, centerY, 100, -Math.PI/2, Math.PI, false)
  ctx.arc(centerX, centerY, 100, this.startRadio, this.endRadio, false)
  ctx.stroke()
}
